Symptoms
If the SQL Server procedure cache consumes too much memory that has several entries in it, and the Query Store is enabled, a memory leak will occur. Additionally, when you execute DBCC PROCCACHE, the value of the num proc buffs column is a fairly big number but that of the proc cache used column is just 0, 1, or 2.
Resolution
This issue is fixed in the following cumulative updates for SQL Server:
Cumulative Update 2 for SQL Server 2016 SP1
Cumulative Update 4 for SQL Server 2016
About cumulative updates for SQL Server
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:
Latest cumulative update for SQL Server 2016
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminology that Microsoft uses to describe software updates.